The present invention relates to a method and program for generating a library.
In recent years, there is a demand for shortening the time for designing a high-integration and high-speed semiconductor integrated circuit device. During the design stage of a semiconductor integrated circuit device, a library, which is generated under certain operating conditions, is used to conduct various verifications on the semiconductor integrated circuit. However, the extraction conditions for configuring the library may differ from a client's actual operating conditions. This may decrease verification accuracy. Thus, there is a demand for the generation of a library that enables verifications to be performed with high accuracy in accordance with actual operating conditions.
When designing a semiconductor integrated circuit device (LSI), such as an application specified integrated circuit (ASIC), the designed LSI must be verified whether the specification required by the client is satisfied. The verification includes determining whether the LSI functions properly under the client's usage conditions (operating conditions of the LSI). Cells forming the LSI are registered in the library. In the design stage, the library includes data indicating the relationship between the operating conditions (temperature and voltage) and the operating characteristics of each cell. The data for the operating characteristics is used in the verification of the LSI.
However, the client's operating conditions may not match the extraction conditions for the library. Therefore, in the prior art, a characteristic library including characteristic values under the operating conditions corresponding to the client's specification is generated (refer to Japanese Laid-Open Patent Publication Nos. 2001-168200 and 2002-222232). The employment of the characteristic library enables the verification of an LSI under the client's desired operating conditions.
The processing performed to generate a characteristic library in the prior art will now be described with reference to the flowchart of FIG. 1.
First, in the scale data generation process S11, characteristic information 12 and operating conditions (P, T, and V conditions) 13, which correspond to a client's specification, are included in a library. In accordance with the characteristic information and the operating conditions, correction coefficients (temperature coefficient and voltage coefficient) are calculated or extracted to generate a scaling file, which includes the correction coefficients. Then, in a library updating process S15, a reference library 16, which stores characteristic information under standard operating conditions (e.g., in a typical manufacturing process, the voltage is referred to as a standard voltage and the temperature is referred to as a standard temperature) is referred to in order to multiply a characteristic value by the correction coefficient to calculate a correction characteristic value and generate a characteristic library 18, which includes the correction characteristic value.